Spring AOP @Before 通知返回值

Question

我是 Spring AOP 的新手，我想知道是否可以從@Before返回一個值到方法並在其中使用這個變量，例如：

@Before("@annotation(CheckUserReservationPermission) && args(username,idReservation)")
public Reservation userCreationAdvice(ProceedingJoinPoint pjp, String username, Integer idReservation) throws Throwable {
    Reservation reservation = reservationServices.findById(idReservation);
    if (!reservation.getUser().getUsername().equals(username))
        throw new PermissionException("You can't delete the reservation with id: " + idReservation);
    return reservation;
}

和我的方法：

@Override
@CheckUserReservationPermission
public void deleteReservationById(String username, Integer idReservation) throws QueryException {
    synchronized(ReservationsSchedulerServicesImpl.class){
        databaseReservationServices.deleteReservationById(username, reservation);  
    }
}

有沒有辦法做到這一點？ 否則我必須重復查詢。 謝謝

更新：使用@Around我可能有這個代碼，但是如何將變量檢索到deleteReservationById方法中？

@Around("@annotation(CheckUserReservationPermission) && args(username,idReservation)")
public Object userCreationAdvice(ProceedingJoinPoint pjp, String username, Integer idReservation) throws Throwable {
    Reservation reservation = reservationServices.findById(idReservation);
    if (!reservation.getUser().getUsername().equals(username))
        throw new PermissionException("You can't delete the reservation with id: " + idReservation);
    return pjp.proceed(new Object[] {reservation});
}

Answer 1

編輯2：

1. 建議

   @Around("@annotation(CheckUserReservationPermission) && args(username,idReservation)") public Object userCreationAdvice(ProceedingJoinPoint pjp, DeleteByIdRequest req) throws Throwable { Reservation reservation = reservationServices.findById(idReservation); if (!reservation.getUser().getUsername().equals(username)) { throw new PermissionException("You can't delete the reservation with id: " + idReservation);} req.setReservation(reservation); return pjp.proceed(new Object[] {req});

   }

2.新請求POJO

 class DeleteByIdRequest {
      Reservation reservation;
      String username;
      Integer idReservation;
    }

3.目標方法

@Override
@CheckUserReservationPermission
public void deleteReservationById(DeleteByIdRequest request) throws QueryException {
    synchronized(ReservationsSchedulerServicesImpl.class){
        databaseReservationServices.deleteReservationById(username, reservation);  
    }
}

請參閱此建議的接口，

檢查他們返回的內容。

1.拋出建議

public void afterThrowing(IllegalArgumentException e) throws Throwable {
}

2.退貨后的建議

public void afterReturning(Object returnValue, Method method,
        Object[] args, Object target) throws Throwable {
}

3.MethodBeforeAdvice

public void before(Method method, Object[] args, Object target)
        throws Throwable {

}

4.MethodInterceptor（Around Advice）

public Object invoke(MethodInvocation methodInvocation) throws Throwable {

}

如果您在第 4 點中注意到只有 around 建議是返回對象。

您必須定義 joinPoint.proceed() 來控制攔截器何時應將控制權返回給原始方法。

在此處檢查簡單示例

編輯：我認為這可以在繼續爭論的幫助下實現
基本上，您可以使用新參數調用proceed()。